Die for extruding collapsible tubes



w.PRuss|NG Il" 1,900,665 f -Marh7,1sxz3.l`

l DIE PoR EXTRUDINGJCOLLAPSIBLETUBES Filed Feb. l4. 1931 2 shee'sfsneei 1." ff] Mardi 7, 1933. W PRUsslNG l 1,900,665

Dix FOR EXTYRUDING coLLABsIBLE TUBES Filed Feb. 4, 1931 2 Sheets-Sheet 2 IN NTOR Miter rusamg' BY .jgoRNEY Patented Mar. 7, 133

UNITED STATES? PATE WALTER PRUssI'N-G, OF BROOKLYN, NEW Yonai, AssIeNoiaJ To VICTOR; METAL PRODUCTS cOarOaATroN; or BROOKLYN, NEW YORK, A CORPORATION or NEW YORK-l ma For. Ex'rmmme GOLLAPSIBLETUBIS lhis invention relates to the die sets used My invention therefore' contemplates 'the' i inthe extrusion of soft metal blanks into collapsible tubes, such las those used for toothparts. The` outermost part whichis not sub- J paste, shaving cream, and-the like, and to the )ected to wear, is permanent and unhardened,I

art of making dies for prolonging the operatin life of such dies'.V

n the. process of making collapsibletubes, a disc Aeither flat or dished, is fed to a female die which is held on the table or=bed in a suitable press, and an elongated male-*die is then brought down upon the disc, thereby squeezing the disc into a conical recess in the female die and causing the metal of the disc to squirt or flow withgreat rapidity inthe direction of the pressure put thereupon by the male die, the metal thinning out during this operation, whereby the thin Wall ofthe tube is extruded and the tube is formed. The outermost diameterv is determined by'the diabove the conical recess and the innermost diameter of the tube is determined by the diameter ofthe lowermost part of the cylindrical portion of the maledie.

Great pressure i's exerted nponthe female die during the extrudingl operation. Attempts have heretofore been made, therefore, to increase thelife of the female die byhard-` ening it about the forming recess thereon' Such attempts'have beenunsatisfactory, becauseY the die must be so thick to resist the pressure, that fit cannot beUproperly hardened to a sullicient distance outwardly of the recess.d The female die, in suchcases, cannot resist the great pressure exerted thereon, and'frequently splits. It must conse r quently be replaced from time to time, with greater or less frequency depending upon the Y as it appears assembled eiciency withwhich it has been hardened.

ltain the'outermost portion thereof unhrd- It is advisable, in such female dies, to main- .ened or comparatively soft and elastic, so that the die may give way sufficiently without breaking to absorb and resist the pressure put thereon. The accurate conditioning of the hardened operative portion in connectionr with a comparatively soft outer portion has heretofore been impossible of attainment,

particularly, because the die has customarily been made of a single piece.

of the bottom part of the femalede, and

spective of possible'breakage of the-'other provision of a female die ,made oftwo or more and designed to'be used over and over, irre- 5 5.

parts-while" theinnermost or operative portion Aor portionson which thewear is4 conor worn out, My invention further oontemplates the provision `ofa simple' andeicient connectlon for holding the die parts together the :remainder of the`fema e die for ,prolonging the life of the die and for controlling the 'cen'trated, ishardened throughout and is so designed as? to vbe .replaceable when'damaged 60 outer diameter -of .the tube formed by the eX- ameter of theopening in the'female die just truding process. My invention also 'con` 70 'templates a process for making land using dies to prolon'gthe life of the ring and of therdie in spite of excessive wear thereof, by conpensating forthe enlargement of the due to wear and due to the lapping or'ret5 grinding. processes which may slightly in; crease its diameter.l My invention'further'- 'and from the drawings, in which,

Acontemplates the provision of simple and em- A Y so of my invention will. r

Fig. 1 .is a diagrammatic-elevation ofa improved diesare designed to'lbe' used.

Fig. 2 is a top plan view ofthe female die on the table or bedgof Xtypical tubev extruding press in which my' Figi. 3 is a front elevation and partial'sec- 90 tion of the same, showing the maleqdie Withdrawn from thefemale die and showing the f forning ring sprung'or deformed/after Wearl J to compensate for its increased diameter..

Fig. 4 is a vertical section of part of the be die andof the guard ring, ushowing the diameter controlling or forming ring when new or unworn and Yin its normal position.

Fig, 5 is a top plan view "of afmodied form Fig. 6 is a partial front elevation and partial section of the same, showing the male A die partly withdrawn.

' In that practical embodiment of my invention. which I have illustrated by Way of example, the press 10 comprises the frame 11 provided With the toggle 12 which operates the cross head 13 carrying the male die` and by means of which the male die 14 is vertically reciprocated. The female die, designated generally by the numeral 15, is suitably held removably onthe table 16 of the press, as will be more fully described hereinafter.

As the male die 14 is reciprocated into and out of the female die, the slugs or blanks which may be flat or dished, are suitably fed to the die horizontally in a manner which need not be here described, and the. blanks are squeezed andextruded into tubes, which are pulled out of the female die by the male die, and then-removed from the male die.

The female die ma'y be constructed in several ways, but in any case, it consists of two or more parts.

Referring now to Figs. 5 and 6, the male die 14 comprises the usual neck 20 which forms the perforated neck ofv thetube, the

dies. As shown, the female die bottom comprises the outer ring 24 provided with a slightly tapered or conical opening 25,. and includes the member 26.

tively soft and lelastic and consequently, un-

` der the pressure of the extruding operation, Agives slightly or absorbs the pressure and hence maylastindeinitely. The wear and stress upon the die is, however, taken up by the hardened inner or center member 26 of "thedie' set. The member 26 is provided with same taper as the inner vsurface of the ring 24 surrounding vthe-,opening 25. Said member,

'26 is forced into the opening" 25 andinto pressed contact with the surface surrounding the opening 2 5, under 'suitable pressure.

I have found that a pressure of about 40 tons isv suflicient to maintainV the die parts ,24. and 26 in their proper positions4 when assembled. I haveafurther found'that a taper of about two degreeson the conical surfaces25 and 27 forms a quite satisfactory angle, making the proper assembly of the die parts possible, and makingit also possibleto disassemble said yparts should it be required to do so.

Said ring 24 isf. 'preferably made lofsteel which is not hardv ened. The ring therefore remains compara# The inner' hardened die member -26 is provided with a cylindrical opening 28, in which operates the knockout pin 30, as will be more fully described hereinafter, said pin in its uppermost position determining the length of the neck of the nished tube. The member 26 is further provided with a conical recess 29 for shaping the conical portion of the collapsible tube, in cooperatlon with the conical surface 21 of the male die. It will be understood that the lowermost limit of the stroke of the cross head is predetermined In order, however, to prolong the operative life of the die set, a separate and independent reversible and removable ring 32 is used to determine the outer diameter of the extruded tube and therefore to determine the thickness of the body of said tube.

Said ring is provided with a normally flat upper surface 33, parallel to the similar lower surface 34, and is further provided with a preferably cylindrical opening 35 surrounded by the wall 36. It will be understood that the corner or edge 37, at the juncture of the lower surface' 34 and the wall 36, determines the outer diameter and thickness, of the tube-extruded by the dies. Said corner 37, therefore, is subjected to the pressure of the metal flowing thereby, and to eater Wear than any `other part of the ring 32. Ordinarily, it would become necessary to discard the ring after the wear at the corner 37 had reached such an amount as to faillvl' to determine properly the diameter' of the extruded tube.` I have, however, provided a new process and means forenabling my new ring to be used even after the corner 37 has been Worn to a econsiderable extent. Toward this end, the upper surfaces -1f7 and 19 and 40 ofihe die bottom ring 24 and member 26 and the die botto`m 31 respectively, are bevelled downwardly and outwardly to a' slight extent. The surfaces 17 and 19 are aligned with eachother'and inclined at the same angle to the horizontal, being separated/ bg a recess as- 18 to avoid unnecessarymac ining. Similarly, the under surface 41 of the guardring 42 is bevelled or inclined at ,the same angle, to make it parallel to the surface 40. When the corner` 37 has become so worn that it fails to function properly, the ring 32 is reversed or turned upside down to bring the corner 38 into operative position. lThe* use of the ring 32 may-then be continued even though it is maintained fiat in the die set. When both corners 37 and 38 become so worn that the ring again fails to function properly, the ring is removed from the die set, and the surface 36 is ground or lapped to a suiicient extent to make it again cylindrical.

In practice, it is onlynecessary to remove about two thousandths of an inch for this purpose. The lapping operation, however, increases the diameter of the wall 36 to a slight extent. To reduce the corner 37 again to its proper diameter, the guard ring is drawn toward the die bottom in a'manner soon to be explained, v whereby the ring 32 is sprung, deformed or distorted to make'it slightly convex upwardly owing to the pressure put thereon by the bevelled 'or inclined surfaces 41 and 40. By so bending, deforming or springing the ring 32, the wall 36 is changed from a cylindrical to a slightly conical surface and the diameter of the corner 37 becomes slightly lessened to a suiicient degree to allowthe ring to function again for the lproper control of the diameter of the extruded tube. .This diameter can be adjusted as desiredby tightening or looseni ing the nut 56. Similarly, when the corner 37 wears out again andbecomes inoperative,

the ring may be again reversed and similar- -ly spring to bring the corner 38 into operative diameter controlling position. This operation may be repeated and the pressure exerted on the ring 32 increased from time to time to prolong the life of the ring, and

of the dies to a substantial extent, particularly in connection with the` replaceable hardened member 26.

The guard ring 42 is provided with an upper surface 43 serving as a guide for the entrance of a blank into the opening 44 thereof. To stop the horizontal movement of the blank and tfo alignfit for-entrance into the die, a guard wall as 45 is provided, projecting above the`surfa'cer43. Said guard-wall stops the horizontal advance or feed of the blank, so that the blank falls through the opening 44 and into the opening 35 of the ring 32, ready for the extruding operation.

To maintain the die bottom 31, -the'ringV 32 and the guard ring 42 in their proper positions, and under the proper pressure,

v these parts are assembled upon a suitable bolster 50 suitably securedremovably to thebed of the machine as by' means of thenuts or bolts 51. An opening as 53 is provided in -53 and 28 which means need not be' shown nor further described.V Said pin serves to release the extruded tube from the female die at the completion of the extruding opera' shoulder 58 of the guard ring and exerting l downward pressure thereon to clamp the parts in place. It will be understood that" the downward clamping pressure of the nut on saidparts may be adjusted as may be found desirable, particularly, for the springf time, or ground and reinserted or deformed as may be necessary to avoid replacement and to prolong the life of the die.

` It will be seen that I have provided simple and eicient means, capable of withstanding hard wear and. extremely durable even though used over long periods in connection with dies for extruding collapsible tubes. It will further be seen that the disadvantages of such dies heretofore pointed out have been overcome by means of my I invention, and that I have produced a -device well adapted to meet the severe requirements of practical use. While I have shown and described certain specific embodiments of my invention, it will be understood that I do not intend to limit myself thereto but desire to claim my invention as broadly as may be permitted by the state of the prior art andthe terms of I the appended claims.

I claim:

1. In a die set for the extrusion of metalV hardened metal having an inner conical sur,-

face surrounding an aperture in the ring, and a hardened metal member having a conical forming recess therein, and provided with an outer conical surface forced into engagement with the inner conical surfaceA of the outer ring, the upper surface of said ring and of said member being inclined downwardly and outwardly, and a male die reciprocating to enter the conical recess t0 squeeze a blank against the conical recess of the member and to force the metal ofthe blank inthe direction of the reciprocation of the male die and thereby to form a tubular wall about the male die.

Y2'. In a dieset for extruding comparatively soft metal blanksinto collapsible tubes, a female die comprising a removablebardened steel center having a recess therein, an-

unhardened steel ring forced about the hardoperating with the recess of the hardened center-to extrude the blank into a tube.

3. In a female die for the extrusion of comened center, and a reciprocatory male die coparatively soft metal discs into collapsible tubes, an outer ring of unhardened metal, and an inner member of hardened metal having a forming recess therein,.and pressed into forced engagement with the outer ring and. removably held thereby.

4. In a female die for the extrusion of comparatively soft metal discs into collapsible tubes, an outer unhardened ring having an inner conical surface surrounding an aperture therein, and a hardened inner diemember forced into said aperture and against said surface and having a forming recess therein.

"5. In a female diefor the extrusion of comparatively soft metal discs into collapsible tubes, an outer ring of unhardened metal, an inner die member having aforming re-` cess therein pressed into forced engagement with the outer ring and-arranged coaXially thereof, the upper surfaces of said ring and said member being bevelled slightly downwardly and outwardly.-

6. In a die set for'extruding blanks into collapsible tubes, a female die having a hardened center portion provided with a conical forming recess terminating at one end atvthe upperl surface of the disc-and terminating at its other end in a cylindrical opening, and aving a slightly conical outermost surface, and an outer unhardened ring more elastic than the center portion and having an inner conical surface of the same taper as the outermost surface ofthe center portion, the center portion and the ring v ,beng assembled by pressure 'coaxialvly thereof tobring said,

conical surfaces into forced engagement, whereby the center portion may be forcibly removed from thering when damaged, and

, a new center portion inserted into the ring.

- male die, said ring having normally flat ends and having an aperture therein arranged coaxially of the-recess, the lowermost corner surrounding the aperture determining the outer diameter of thetube formed from the blank, and means for distorting the forming ring to bringl the normally -flat lower surface thereof into contact with the bevelled upper Jsurface ofthe .female die and to thereby reduce the diameter of said corner, said means `forming recess therein,'aligned and downwardly and outwardly bevelled upper surfaces on the ring and the die member, and a forming ring on the female die adapted to be sprung conveXly upwardly with its lower' effective inner diameter.

10. In a die set for eXtruding blanks into collapsible tubes, a reversible forming ring f or determining the outer diameter .of 'the tube extruded by the die set, and an adjustable member for deforming the ring by pres sure thereon, and byvarying the least innermost diameter thereof.

11. In a die set for extruding blanks into collapsible tubes, a reciprocatory male die for determining the innermost diameter of.

the extruded tube, a stationary cooperating female die having a bevelled upper surface, 4

a forming ring for determining the outermost diameter of the tube, and .a vertically adjustable member for putting pressure upon,

mine the effective innermost diameter of theA forming ring. j l

- 13. In a die set for extr'udingblanks into collapsibletubes, -a female die having a bev-` elled upper surface, a guard ring having a similarly bevelled lower surface, a normally flat reversible forming" ring between said surfaces, and adjustable means for pressing i the forming ring toward the female die to hold the forming ring in operative position and to determine the effective innermost diameter of the forming ring', said effective diameter being located. at the juncture of the lowermost and innermost surfaces thereof and determining theA outermost diameter of the`tubeand a male die reciprocating into and out of the female'die and determining the innermost diameter -of the tube.

1.4. In a die set for extruding blanks into collapsible tubes, a female die having a central aperture therein, -and having a coaxiallyf arranged conical recess terminating at its upper end at the upper face of the die,- and l at its lower end joining the upper end of the' aperture, an independent reversible forming ring having; an opening there- Leccese through cooperating with said conical recess to determine the outermost diameter ofo the tube, and means for pressing said forming ring against the die, for retaining said-die and ring in operative position, and for controlling the shape of said ring, and thereby determining the diameter of the corner at the juncture of the lowermost surface of the ring and the wall of the opening therein.

l5. In a die set for extruding blanks into collapsible tubes, a female die comprising an outer unhardened ring, part of the upper surface of the ring being inclined downwardly and outwardly, a hardened metal member forcibly inserted into said ring and forcibly removable therefrom, said member having its upper surface aligned with Ithe inclined upper portion of the ring, and having a conical recess therein having its greatest diameter at said upper surface of the member, and a reversible and a deformable forming ring arranged on said die and cooperating therewith to determine the outermost diameter of the tube. v

16. In a 'die set for extruding blanks into collapsible tubes, a female die having a conical recess therein terminating at the upper surface of the die, said upper surface being inclined slightly downwardly and outwardly, a guard ring for guiding blanks into the die, said guard ring having a similarly inclined lower surface, a reversible forming ring having normally ilat upper and lower surfaces engaging `the respective inclined sur,- faces of the guard ring and the die, and adapted to bedistorted by the relative adjustment of the guard ring and the die to vary the eiective innermost diameter of the'forming ring. f

17.- In a die set `:for extruding blanks into collapsible tubes, a bolster havin an opening therein, an externall thre tion arranged coaxially o the opening, a nut internally threadedfto engage saidthreaded ring between the guard r' forming ring having norm lower surfaces.

19. The process of reducing the effective and the die, said y iiat upper and diameter of the forming ring of a die after said diameter has been increased by wear,

f comprising lappin the forming ring to over' come the effects o wear, and to increase its clined upper surface, a hardened inner steel die member forced into said ring and held thereby, and having a conical recess therein terminating at the upper surface of said member, said upper surface being inclined similarly to and aligned with the upper sursimilarly inclinedvlower face, and a forming blanks inw face of the outer ring, a guard ring havin a projection for stopping horizontall ed blanks, and having an opening therein for the receptionof said blanks, said guard ring having a similarly inclined lower surface, a

normally flat forming ring between-the guard ring `and the die, said forming ring having an openin therein for thereception of the blank falling through the guard ring, and

means for varying the diameter of the lower-v most part of said o ening in the forming ring e comprising a. mem erfor'forcing the guard ring toward the dieand thereby distorting the forming ring, and a reciprocatin male die cooperatin with the female die or determining the s ape of the end of the tube/and the innermost diameter thereof. t

WALTOER PRUSSING.

ed projecfI projection, and having an opening therein constricted at its 'upper end to form an internal shoulder, a female die having a conical uppermost recess, 'and a communicatingY cylindrical aperture .therethrough, a projection on the lower face of the die inserted into the opening of the bolster, an independent reversible forming ring on the die, and a guard'ring `on the forming ring, thenpper surface o f the die and the lower surface of the form' ring being parallel and inclined out of the horizontal, said ard ring having an outwardly projecting s oulder engaging the internal shoulder of the nut w ereby rotation of the nut varies the pressure on the forming ring, and whereby said forming ring i may be distorted between the inclinedfaces of the d ring and the die. y

a die setfor extruding blanks into collapsible tubes, a female die having an inupperV face, a guard ring" having a 

